{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-43271",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-43271"
  ],
  "published": "2026-05-06T11:29:17Z",
  "summary": "md-cluster: fix NULL pointer dereference in process_metadata_update",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd-cluster: fix NULL pointer dereference in process_metadata_update\n\nThe function process_metadata_update() blindly dereferences the 'thread'\npointer (acquired via rcu_dereference_protected) within the wait_event()\nmacro.\n\nWhile the code comment states \"daemon thread must exist\", there is a valid\nrace condition window during the MD array startup sequence (md_run):\n\n1. bitmap_load() is called, which invokes md_cluster_ops->join().\n2. join() starts the \"cluster_recv\" thread (recv_daemon).\n3. At this point, recv_daemon is active and processing messages.\n4. However, mddev->thread (the main MD thread) is not initialized until\n   later in md_run().\n\nIf a METADATA_UPDATED message is received from a remote node during this\nspecific window, process_metadata_update() will be called while\nmddev->thread is still NULL, leading to a kernel panic.\n\nTo fix this, we must validate the 'thread' pointer. If it is NULL, we\nrelease the held lock (no_new_dev_lockres) and return early, safely\nignoring the update request as the array is not yet fully ready to\nprocess it.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-43271"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a61c1bc84c4a0f1e7c2fe55b0f43d7d94af4adf1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/dec123825c1ed74d98fd5fc7571a851dea4f46ff"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/721599e837d3f4c0e6cc14da059612c017b6d3ec"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/dceb5a843910004cb118148e267036104fc3ee43"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f150e753cb8dd756085f46e86f2c35ce472e0a3c"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}